Structure for fluorescent dial panel and method of making the same



Jan. 18, 1949.

Patented Jan. 18, 1949 UNITED STATES PATENT OFFICE STRUCTURE FORFLUORESCENT DIAL PANEL AND METHOD OF MAKING THE SAME 3 Claims.

This invention relates to a multi-colored fluoM rescent panel which canbe used to manufacture radio dials, and to a process for making suchpanels. A fluorescent radio dial generally consists of a panel made of1ltranslucent plastic, upon which is applied a fluorescent pigment whichconstitutes the dial markings, all of the rest of the surface of thepanel being opaqued out. The uorescent pigments are generally applied tothe plastic panel by a silk screening process. In the past, if the panelwas to have a plurality of different colored scales thereon the silkscreening process had to be repeated for the respective colors.Therefore such dials were necessarily expensive. It ls an object oi thepresent invention to provide a panelwhich can be used in the manufactureof multi-colored radio dials, wherein the panel itself is of a pluralityof colors, one for each of the colored scales desired on the panel, sothat all ofthe different .colored scales may be formed on the panel by asingle operation.

The panel of the present invention, which is to form a radio dial,consists of a seamless sheet of transparent or translucent fluorescentplastic of suflicient thickness to give it the necessary rigidity andstrength for the uses intended, and of different colors at dilerentareas of the sheet surface.

It is another object of the present invention to provide an improvedmethod oi making a panel of the above mentioned character. In accordancewith the preferred embodiment of the present in vention a suitableplastic forming liquid, having incorporated therein a suitablefluorescent pig ment, is placed in a rectangular container. Afterpartial or complete hardening of the liquid another mass of plasticvforming liquid, having incorporated therein a fluorescentV pigment ofanother color, is placed above it. Above that second mass of plasticforming liquid I may, optionally, deposit one or more additional layersof plastic forming liquids, each having incorporated therein fluorescentpigments of the desired colors, and each being placed in the containerafter the pren ceding layer has hardened. This mass of liquid then formsa rectangular transparent or translucent brick of plastic material, saidbrick .com sisting of layers of different colors integrally united intoone unitary structure. The brick thus formed may then be sliced intoslices or sheets of the requisite panel thickness, say slices ofapproximately 1&0 of an inch, more or less, de pending upon the physicalstrength required of the panel to be formed. vEach one of these sheetsmay then be silk screened to form on the sheet 2 hence the dial markingson the different parts of the sheet will be of the characteristic colorsof those parts.

The attainment of the above and further objects of the present inventionwill be apparent from the following specification taken in conjunctionwith the accompanying drawing forming a part thereof.

In the drawing:

Figure l is a perspective View of a block or brick from which radiopanels of the present invention are to be made;

Figure 2 is a perspective View of a panel cut from the brick or block ofFigure 1;

Figure 3 is a perspective View illustrating the method of printing thedial markings on the panel of Figure 2; and

Figure 4 is a iront View oi a radio dial panel embodying the presentinvention.

In Figure l I have shown a multi-layered brick l, of material which ispervious to light, preferably a transparent or translucent plastic,having iiuorescent material incorporated therein. In this instance thebrick comprises three layers, namely, a lowerrnost layer 2 colored red,an intermediate orange colored layer 3, and a top green colored layer 4.A greater or lesser number oi layers may be provided, and the colorschosen are arbitrary. The respective layers may be of mutually differentcolors or may be of diferent shades of the saine color.

The brick or block l may be formed by pouring into a container a body ofliquid thermoplastic forrning material 2 having incorporated therein asuitable fluorescent pigment of the appropriate color. After partial orcomplete hardening of this `material t another body of liquidthermo-plastic forming material having other colored fluorescent pigmentincorporated therein is gently poured on top of the previous layer` Thisis repeated for as many layers as desired, each layer being poured inafter partial or complete hardening of the previous layer. There is thusformed a solid blo i of inulti-layered plastic, the layers being ofdierent colors or shades. The layers 3 and t may be he saine or ofdifferent thicknesses as desired in the finished product. After thematerial has fully solidified it is removed from the container 5 or,more appropriately, the container, which may be made of sections, isremoved iroin the brick. While this represents one method of making themulticolored laminated plastic brick the same may be made in any otherdesired manner. For instance, three slabs 2, 3 and 4, oi differentlycolored uorescent thermplastic material, may be placed one on top of theother and suitably secured together into one unitary structure in anyother desired manner, as by the use of a plastic cement or .as by theapplication of heat and pressure thereto. The resulting product is alaminated brick of dierent colored thermo-plastic materials united intoone integral structure.

The brick I is then sliced crosswise, as by a line of cut 6, to formsheets such as the sheet 'I (Fig. 2) of the appropriate thickness, say1%-,0 of an inch to 1/8 of an inch or more. The sheet is suiicientlyrigid to be self supporting in a radio set. This sheet, therefore,consists of a lowermost red strip 2', :an intermediate orange strip 3',and an uppermost green strip 4'. The different colors are inthe form ofstrips extending across the sheet with the longitudinal edges ofadjacent strips in edge to edge abutment and united together to formseamless joints, all three strips constituting one unitary integralsheet of different colors at different places on the sheet. The sheet 'Iis fluorescent, that is, when activated by ultra violet or near ultraviolet light it will glow in the respective characteristic colors.

Different radio scales are then formed on the respective strips 2', 3and 4 by any process which opaques out the entire surface of the stripexcept where the markings are to appear. The resulting product is anintaglio print. It may be made, for instance, by the silk screenprocess, as illustrated in Figure 3. In this gure there is shown a silkscreen IIJ which has different scales II, I2 'and I3 formed thereon byopaque markings on the screen, each of the scales extending lengthwiseof the screen. The screen is laid over the sheet 'I and an opaquepigment is applied to the surface of the sheet 'I through the screen I0.The pigment penetrates the screen and covers the entire sheet 'I exceptat the places where there are the opaque scale markings II, I2 and I3 onthe screen. At those places no pigment reaches the surface of the sheet1, fand therefore the sheet 'l remains exposed only at those placeswhere the opaque scale markings appear on the screen I0. Upon removal ofthe screen from the sheet 'I the entire surface of the sheet 1 has beenopaqued out except where the markings occur. The exposed partsconstituting the scale markings are therefore green along the strip 4'where the scale II is formed, orange on the strip 3 where the scale I2is formed and red on the strip 2 where the scale I3 is formed. There isthus formed in a single operation an intaglio print of three scales onthe sheet 1, the scales being each of different colors. The sheet 'I isthen ready for mounting as a radio or instrument panel.

While I have here spoken of the sheet l as constituting a radio panel,it is, of course, apparent that the sheet 'I can constitute a panel onany instrument board where it is desired to have two or more adjacentscales of diierent colors. This may be true in an automobile, on thecontrol board of an aircraft, or wherever 'a multi-dial instrument panelis provided. When the panel is illuminated by a source of ultra violetor near ultra violet light the fluorescent plastic which is exposed atthe dial markings glows with a visible light so that the respectivescales or dials are sharply apparent. The source of ultra violet or nearultra violet light for illuminating the panel may be mounted behind thepanel, as part of the structure or board whereon the panel is mountedor, if desired, the panel may be illuminated by a source of ultra violetor near ultra violet light located outside of the instrument, that is,located within the room but outside of the instru- 4. ment. In eitherevent the dial markings on the sheet '1, and only the dial markings,will be Visible, and they willbe visible in the respective colors ofVthe strips 2', 3' and 4. It is thus apparent that by using amulti-colored fluorescent sheet 'l' it is possible to make amulti-colored plurality of Idials by a single operation, thus reducingthe cost of making multi-colored instrument dials. The reference, inthisdescription, to different colors is intended to include dilerentshades of the same color.

In compliance with the requirements of the patent statutes I have hereshown and described a preferred embodiment of my invention. It is,however, to be understood that the invention is not limited to theprecise embodiment here shown, the same being merely illustrative 0f theprinciples of the invention. What is considerednew and desired to besecured by Letters Patent'is:

1. A fluorescent sheet of light pervious material comprising stripsunited together edge to edge into an integral seamless sheet, the stripshaving incorporated therein colored fluorescent pigments, the pigmentsin successive strips being of dierent colors, and a scale formed on eachstrip b-y an opaque lm which covers one surface of the sheet and hasdial mark openings thereinv whereby the colors of the respective scalesare the different colors of the respective strips.

2. A multiple scale dial for an instrument wherein different scales areof different colors, comprising a sheet of light pervious materialdifferent portions of which are of different fluorescent colors, and anopaque covering for -onesurface of the sheet, said covering having dialmark openings therethrough over the dilerent colored portions of thesheet.

3. The method of making a multi-scale dial whereon the different scalesare of different colors which comprises providing a foundation sheethaving fluorescent pigment arranged across Vthe sheet in strips and withdiierent strips of viiuorescence of different colors, then formingscales on all of the strips by applying an opaque nlm over an entiresurface of the foundation sheet except where the dial markings are toappear, whereby the dial markings appear in the different colors offluorescence of .the respective strips.

JOSEPH M. GORDON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS The ABC of Luminescence, The New Jersey Zinc Co.,Front St., New York, N. Y.

